Magnetic hard disk drives retrieve and/or store data in computers and other consumer electronics devices. A magnetic hard disk drive includes one or more heads that can read and write information on a corresponding magnetic surface of a spinning disk. For convenience, all heads that can read are referred to as “read heads” or “heads” herein, regardless of other devices and functions the read head may also perform (e.g. writing, micro-actuation, flying height control, touch down detection, lapping control, localized disk media heating, etc). Each read head is a sub-component of a head gimbal assembly (HGA). The HGA also includes a suspension assembly for holding the head and providing a plurality of electrical connections thereto. The suspension assembly typically includes a fragile laminated flexure to carry the electrical signals to and from the head.
The head typically comprises a slider that includes an air bearing surface (ABS) that faces the magnetic disk surface and a trailing face. A magnetic transducer and a plurality of head bond pads are typically disposed on the trailing face of the slider. The mounting face of the slider is typically permanently bonded to a tongue portion of the fragile laminated flexure by an adhesive, in a position such that the plurality of head bond pads are aligned with corresponding bond pads on the laminated flexure.
Conventionally, the magnetic transducer on the trailing face of the slider can write tiny magnetic transitions on the magnetic disk surface by applying sufficient magnetic field to a desired microscopic disk surface location, to overcome the coercivity of the disk surface material there and thereby change the remnant field there. The magnetic transducer also includes a read sensor that must be capable of sensing magnetic transitions written along very narrow concentric tracks around the disk surface. For example, the width of the read sensor may be required to be less than 50 nm in modern magnetic recording applications. As the areal density of data written on magnetic disk media further increases, ever-narrower read sensors are required.
Conventional methods to fabricate read sensors of narrow width may suffer from inadequate cleaning of photo mask residue and/or undesirable metal re-deposition or corrosion during certain manufacturing steps, leading to unreliability in ultimately producing the desired read sensor widths. Accordingly, there is a need in the art for improved methods to reliably fabricate very narrow read transducers (e.g. with read widths of 30 nm or less) for magnetic heads, practical for high volume manufacturing with acceptable yield and cost.